Implantable neurostimulators are effective at treating various disorders such as epilepsy and depression. A neurostimulator is implanted in the patient and connected via one or more electrodes to a target nerve, such as the vagus nerve. Current from the electrical signal provided by the neurostimulator or action potentials evoked by the stimulated target nerve can propagate to a non-target nerve (including nerves nearby the target nerve as well as specific non-target fibers within the target nerve) and non-target muscle tissue adjacent to the electrodes. As a result, such nearby tissues may be stimulated thereby resulting in wasted energy that is non-therapeutic and which may in addition cause undesired side effects such as contractions of the muscle tissue. For example, it is possible for vagus nerve stimulation to excite the muscles at or near the patient's vocal cords thereby potentially causing hoarseness. While generally regarded as benign, the excitation of muscle tissue and the resultant hoarseness may be uncomfortable to the patient and is at any rate undesired, wasteful and non-therapeutic. Ameliorating the foregoing problems while improving the efficacy of the underlying therapy provided by the neurostimulator is desirable.